UNIVERSITY 



OF 



and New rivers no leveling whatever is necessaiy for irrigation, the 

 surface being smooth, level, and practically devoid of vegetation. 



Sal ton River enters the United States in the southeast corner of T. 

 17 S. , R. 15 E. , and flows in a general northerly direction to a point 

 north of the area mapped, where it turns northwest and eventually 

 empties into Salton sink. For the first 25 miles of its course in the 

 United States its banks are low; but farther north bluffs 40 to 60 feet 

 high are found on either side. New River crosses the international 

 boundary 7 miles west of the Salton, flows northwest for 7 miles, 

 makes a great bend toward the west, and flows back northeast, cutting 

 the area mapped in the northwest corner of T. 14 S. , R. 14 E. , making 

 a large area between the two rivers which is considered the best part 

 of the delta in this country. Both the rivers are dry except in time 

 of the highest floods in the Colorado, when water breaks over the 

 divide and runs in them for a short time. 



The areas shown on the soil map as sand dunes are covered with 

 dunes and hummocks 3 to 15 feet in height. The leveling of such 

 land will be found expensive, and at the present prices assigned to land 

 will not prove profitable. However, should transportation facilities 

 become better and land under cultivation bring a higher price than is 

 now the case much of this dune land can be leveled and reclaimed. 

 By far the greater part of the dunes are free from harmful quantity of 

 alkali salts, and the porous nature of the material will prevent the rise 

 of the alkali if the level of standing water is kept so low that the 

 upward capillary movement is unable to raise the w r ater from the water 

 table to the surface of the ground. 



Around the western, southern, and southeastern sides of Mesquite 

 Lake the lands are in places badh* gullied and the amount of good 

 land is small. Other than these few exceptions the land of the desert 

 is beautifully leveled for irrigation and requires but the throwing up of 

 small levees to permit irrigation. 



The topography is shown by the contour lines upon the soil map on 

 page 7. These contour lines are made from levels along section lines, 

 and therefore do not show the minor details of topography. We are 

 indebted to the California Development Company for the base and 

 topographic map. 



All of this part of the delta is below sea level. The basin extends 

 to Salton Sink, which is about 280 feet below sea level. The basin is 

 surrounded by a well-defined beach line, which is approximately at 

 sea level, showing that there has been very little accumulative eleva- 

 tion or depression since the basin was a part of the ocean. The favored 

 explanation of the formation of the country is that the Colorado River 

 filled in the basin near its mouth, the greater deposition being nearest 

 the river, until this part of the sea was cut oft', and became an inland 

 lake, from which the water has evaporated. 



